Cellular Blocks - Concrete Block Association

Cellular Blocks
Applications
Cellular blocks can be used as a direct replacement for solid blocks except where
the most onerous conditions exist such as maximum wall mass for airborne sound
insulation. By selecting the correct specification, cellular blocks can be used in the
following common applications:
• Infill in framed structures
• Providing improved insulation as the inner leaf to external cavity walls
• Outer leaves of cavity walls when protected e.g. render, tiling etc.
• Single leaf external walls when protected e.g. render, tiling etc.
• Internal partitions
• Sound separating walls when supported by acoustic test evidence
• Below dpc internally or externally
Site Considerations
Cutting
Blocks containing splitting aids (double thickness central web and/or transverse slot)
are available from most manufacturers in most sizes. Alternatively blocks can be sawn
or split on site taking the appropriate safety precautions or, alternatively, supplied
pre-cut by the manufacturer.
Chasing
Chasing of a cellular block wall can be accommodated. The depth of vertical chasing
should be restricted to not greater than 1/3 block thickness or 1/6 the thickness for
horizontal chases. In addition, the depth of the chase should be restricted to ensure
that a minimum shell thickness of 15mm is maintained between the bottom of the
chase and voids.
Fixings
Standard duty fixings (plastic plug and screw) are easy to install into all types of cellular
blocks and are suitable for most domestic fixing applications (e.g. radiators, kitchen
cupboards, bookshelves etc).
Where heavy duty fixings are required for commercial/industrial applications, standard
bolt type fixings can be used through the solid sections of the block or alternatively,
specialist proprietary fixings can be employed.
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CBA Technical Helpline 0116 222 1507
© The Concrete Block Association 2007
Although The Concrete Block Association does its best to ensure that any advice,
recommendation or information it may give is accurate, no liability or responsibility of any
kind (including liability for negligence) is accepted in this respect by the Association, its
servants or agents.
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